Sensor and method for rapid in situ detection of toxic gases

A sensor and method for the rapid detection of fluoride containing gaseous species specifically the chemical warfare agents Sarin and Soman nerve gas, in which a chemically sensitive composition containing dye indicator molecules complexed with a heavy metal salt is exposed to an environment under surveillance for toxic gasses. In one embodiment the sensing composition is introduced into a polymer-based substrate. The detection composition reacts with hydrogen fluoride which is a decomposition by-product of Sarin and Soman gas so as to change the color of the dye indicator, in one embodiment being pentamethoxy red, that is to change the color of the polymer-based substrate from colorless to a dark purple color. The complex of pentamethoxy red with the exemplary heavy metal salt, zirconyl chloride, is specific for Sarin and Soman nerve gas; it does not react to certain other toxic gases. In various embodiments a hydrolyzing agent is introduced in the polymer-based substrate to improve the detection reaction sensitivity and to increase the reaction rate and decrease the detection time for sensor chemistry.